Dome structure for mantle type lantern



March 20, 1956 GRAETZ 2,739,229

DOME STRUCTURE FOR MANTLE TYPE LANTERN Filed Dec. 5, 1952 2 Sheets-Sheet l 'I l l 6 f6 ra l I I INVENI'OP:

FRITZ GRAE-TL BY: I I I t I March 20, 1956 F. GRAETZ DOME STRUCTURE FOR MANTLE TYPE LANTERN 2 Sheets-Sheet 2 Filed Dec. 5, 1952 INVENTOA.

FRITZ GR a-r z.

United States Paten'tO DOB IE STRUCTURE FOR MANTLE TYPE LANTERN Fritz Graetz, Altena, Westphalia, Germany Application December 5, 1952, Serial No. 324,214 Claims priority, application Germany April 4, 1952 12 Claims. (G. 240-51) Lamps burning liquid fuel delivered under air pressure are in general provided with a so-called internal chimney which, on the one hand, removes the products of combustion and, on the other hand, forms together with a hood an annular space which ensures the induction, protected from draughts, of the primary air. At the same time, the internal chimney serves as a support for a mixer tube and for a mantle attached thereto by a collar or the like.

Hitherto known internal chimneys comprised a cupshaped member surrounded by an upturned border in the form of a collar the edges of which were welded together with an air chamber and the cup-shaped member. A threaded mixer tube was attached by two nuts to a bridge on the aforesaid cup member.

These known designs had various disadvantages. In the first place, the cylindrical part of the internal chimney, shaped from an upturned border, could never be made exactly circular; in the second place, this arrangement did not provide a perfect seal between fresh air and the products of combustion, although such sealing is of decisive importance to the perfect functioningof the lamp. In particular, it was possible for the products of combustion to pass through the open space above the air chamber from the inside of the chimney into an annular primary air chamber. Furthermore, it is extremely difficult to adjust as accurately as is necessary the distance between the mixer tube and the jet of the known designs, and the adjustment is never really accurate and takes .a long time. In addition, the bridge which is located low down in the known designs-impedes the removal of the products of combustion and, due to its low position, it

impedes the requisite good heating of the mixer tube which is desirable for the satisfactory functioning of the lamp.

Extensive experiments with the mixer tube additionally heated by electricity, have shown that light of higher candle power is obtained when almost the whole length of the mixer tube is exposed to the hot products of combustion. Experience has shown that lamps lose a great deal of their illuminating power when the hood is put on, because, in the first place, products of combustion have access to the primary airand, in the second place, when there is a minus tolerance in the distance between the mixer tube and the jet, a shortage of primary air occurs.

The present invention proves that the hitherto known internalchimneys had great disadvantages and it accordingly provides an internal chimney, deepdrawn in one piece and with the shape of its upper edge conforming to the outlines of the hood (and for which it may be made to serve as a carrier), a bridge being provided level with the upper edge, which bridge may be formed with advantage from the closed end of the pot-shaped deepdrawn component. Alternatively, this bridge can, of course, be welded in place. This bridge has, advantageously, edges (bent upwards or downwards) through which protrude fixing means, advantageously screws, which are screwed into tapped holes in the mixer tube. Underneath, one end of the bridge there is, in the cylindrical portion of the l) of: internal chimney, a slot which receives the air chamber. Alternatively, the air chamber may be shaped from the material of the internal chimney proper, for example by drawing or beading it, with a cover welded on, if desired. A leg of the mixer tube extending into the air chamber below a venturi waist can be made of such length that it rests on the upper portion of the evaporator or on the jet. This leg is perforated foradmission of the primary air. Alternatively, this leg can be designed quite short, because by virtue of the adjustability of the mixer tube according to the invention the distance between the mixer tube and the jet can be regulated as required.

The accompanying drawings show one example of care rying out the invention, in which:

Fig. 1 represents a section through the upper portion of the lamp,

Fig. 2 is a front elevation of the the invention, and

Fig. 3 is a plan view thereof.

In the drawings an internal chimney 1 rests on a carrier ring 2. A hood 3 rests at 4 on the internal chimney 1, whereby a tight seal between the internal chimney 1 and the hood 3 is obtained. In addition, the hood 3 is concentric with respect to the carrier ring 2. The upper portion of the internal chimney 1 has slots 5 partially flanged upwardly and forming lateral walls 6 of a bridge 7. In the lateral walls 6, approximately in the axis .of the mixer tube, slots 8 are provided to guide screws 9 which are screwed into tapped holes 10 in the mixer tube 11. One leg of the mixer tube 11 extends into the air chamber 12 which is located in a slot in the internal chimney and into which, through a second slot, an evaporator 13 and a jet 14 extend. That portion of the mixer tube 11 which extends into the air chamber 12 is formed with slots 15 internal chimney of and'rests with its end 16 on the evaporator 13. The other leg of the mixer tube 11 is'supported by a distance piece- 17 within the air chamber 12 and carries at its bottom end a gas chamber 13 with a ceramic collar piece 19 screwed to it. An incandescent mantle 20 is attached to the collar piece 19. Below the bend in the mixer tube 11 there is a venturi waist 22. In the hood 3 there is also a set of apertures 23 for the primary air. An annular air space 24 is formed between the hood 3 and the internal chimney i.

The internal chimney of the invention functions in the following manner:

The chimney 1 rests firmly on the carrier ring 2 and the hood 3 rests at 4 on the chimney 1 so that in this area a tight seal between the chimney 1 and the hood 3 is obtained. At the upper portion of the chimney 1 is a bridge 7 with its lateral walls 6 and when the screws 9 are unscrewed the mixer tube 11 can slide freely in the slots 8 in the lateral walls 6, making it easy to regulate within the requisite limits the distance between the mixer tube 11 and the jet l4.

The primaryair entering through the apertures 23 into the annular space 24 and thence into the air chamber 12 passes through the slots 15 into the mixer tube below the venturi waist 22 where it mixes with fuel vapour issuing from the jet 14.

The lateral chimney with adjustable mixer tube according to the present invention has the following advantages:

In contradistinction to hitherto known designs which, as mentioned above, consist of a cup-shaped member and an upturned border spot-welded to it, the internal chimney of this invention is deepdrawn in one piece which ensures the complete and highly accurate circularity of the internal chimney and renders possible very close working limits between the internal chimney and the hood, which in turn ensures a tight seal between the internal chimney and the hood, the seal being further improved by the fact that the hood, contrary to previous practice, does not rest on a carrier ring such as 2 but on the internal chimney as at 4. T he hitherto known internal chimneys consisting of a cup and an upturned border were not only non-circular as a result ofthe welding stresses set up but they were nottruly cylindrical either. In addition, when an internal chimney is shaped from an upturned border theupper edge can only very incompletely be drawn inwards and it is never possibleto obtain a smooth bearing surface for the hood on the top edge because it does not rest as at 4. As the result of the combination of these facts, when the hood was lifted off, the internal chimney was frequently removed together with it if it had seized in the hood, and this often caused the destructionrof the mantle.

The internal chimney of the present invention further makes it possible to dispose the bridge (which in the hitherto knowndesigns was placed at the edge between the cup and the collar) upwards towards the edge of the internal chimney, approximately to the level of 4, because the deepdrawing of the internal chimney and the. subsequent provision of theslots automatically produce this bridge. This has enabled the internal chamber of the invention to have slots stamped into the bottom ofthis pot-shaped internal chimney and parts of the bottom to be turned up so that an extremely rigid bridge is formed which is organically connected with the internal chimney and enhances the rigidity of the upper portion.

This elevated position of the bridge now makes it easy to displace the mixer tube within certain limits in an'axial direction By slighty unscrewing the fixing screws 9 these screws, and with them the mixer tube, can be adjusted in the slots 8. I

Since it has been established in actual practice that in the manufacture of the individual components certain variations cannot be avoided whereas it is essential for the perfect functioning and maximum candle power of the lamp that an accurate distance between the jet and the mixer tube be maintained, the easy adjustability of the mixer tube of present invention is a considerable advance in the, art. Furthermore, this enables the easy initial adjustment of the mixer tube and also facilitates subsequent adjustment, such for example as when the use of a different fuelor dilferent atmospheric conditions require an adjustment of the distance of the jet from the mixer tube. To render the adjusting of the mixer tube easier still, the mixer tube leg located above the evaporator is made longer in accordance with the invention and abuts with its bottom edge on the jet or on the evaporator. For the admission of the primary air this leg is provided with slots which are so designed that the optimum quantity of primary air is admitted and at the same time the jet can be observed.

The design of the internal chimney of theinvention enables the venturi waist to be located in that portion of themixer tube'where it can be most eflective. The centering of the mixer tube leg which carries the incandescent mantle in respect of the internal chimney is ensured by thepresent invention in simple manner by providing a distance piece- 17 between air chamber i2 and mixer tube 11.

By virtue of the fact that the internal chimney of the invention positively precludes the penetration of the products of combustion into the primary air and thatit is possible to-adjust accurately the distance of the mixer tube, it is possible to obtain so'advantageous a mixture that lamps provided with this internal chimney produce a light of much higher candle power than was possible with the hitherto known internal chimneys. to manufacture than were the hitherto known internal chimneys.

WhatIclaim is:

1. In a lamp device, in combination, an annular support member; a tubular chimney member resting at its bottom on said annular support member, said chimney member being open at its top and having a transverse bridge portion, said bridge portion having flange means extending axially of said chimney member, said chimney member having an air chamber opening; externally there-- Moreover, it is simpler of; fuel vaporizing means extendinginto said air 'chamber; mixing tube means opening at one 'end into said air chamber and carrying a burner means at its other end, said mixing tube means being adjustably connected to said flange means of said bridge portion for axial movement to different positions; and a hood member extending over said chimney member and connected thereto adjacent the upper edge thereof in fluid tight engagement-therewith,

said hood member being formed with apertures in the por-' tion thereof above the top of said chimney member- 2. In a lamp device, in combination, an annular support member; a tubular chimney member resting atits bottom on said annular support member, said chimney member being open at its top and having a transverse bridge portion extending across its top, said bridge portion having flange means extending axially of said chimney member upwardly from the top thereof, said chimney member havingan air chamber opening externally thereof; fuel vaporizing means extending intosaid air chamber;

mixing tubemeans'opening at one'end into said airchambe r and having burner means at its other end; adjusting means carrying said mixing tube means and being adjustably connected to said flange means ofsaid bridge portion for axial movement to different positions so as to adjust the position of said'mixing tube means; and a hood member extending over said chimney member and connected thereto adjacent the upper edge thereof in fluid tight engagement therewith, said hood member being formed with apertures in the portion thereof above the top of said chimney member.

3. In a lamp device, in combination, an annular support member; a tubular chimney member resting at its bottom on .said annular support member, said chimney member'being open at its top and beingformed with a transverse bridge portion extending across its top,;said.

bridge portion being formed with lateral flanges extending axially, of said chimney member upwardlyfrom the top thereof, said chimney member having-an air chamher opening externally thereof; fuel vaporizing means extending into said air chambenmixing tube means opening at one. end into said air chamber and carrying a burner means at its other end; adjusting means carrying said mixing tube means and'being adjustably connected to said lateral flanges of. said bridge portion for axial movement to different positions so as to adjust the position of said'mixing means; and a hood member extending over said chimney member and connected thereto adjacent the upper edge thereof in fluid tight engagement therewith,

said hood member being formed with apertures inthe portion thereof above the top of said chimney member.

4. In a lamp device, in combination, an annular support memberja tubular chimney member resting at its bottom on said annular support member, said chimney member being open at its top and being formed with a transverse bridge portion extending across its, top, said bridge portion being'forrned withupwardly extending lateral flanges formed with slots extending axially of said chimney member, said chimney member having an air chamber opening externally thereof; fuel vaporizing meansextending'into said air chamber; mixing tube means opening at one end into said air chamber and having i burncrmeansat its other end, said mixing tube means having. adjustable connecting means extending into-and movable along said slots in said flanges for mounting said mixing tube means on said flanges in different positions axially ofsaid chimney member; and a hood member extending over said chimney member and connected thereto adjacent the upper edge thereof in fluid tight engagement therewith, said hood member being formed with apertures in the portion thereof above the top of said chimney member. I

5. In a lamp device, in combination, an annular support member; a tubular chimney member resting at its bottom on said-annular support member, said chimney,

member beingopen at its top and being formed with a transverse bridge portion extending across its top, said bridge portion being formed with upwardly extending lateral flanges formed with slots extending axially of said chimney member, said chimney member being formed at one side with an air chamber opening externally thereof; fuel vaporizing means extending into said air chamber; mixing tube means opening at one end adjacent said fuel vaporizing means into said air chamber and having burner means at its other end, said mixing tube means having adjustable connecting means extending into and movable along said slots in said flanges for mounting said mixing tube means on said flanges in different positions axially of said chimney member; and a hood member extending over said chimney member and connected thereto adjacent the upper edge thereof in fluid tight engagement therewith, said hood member being formed with apertures in the portion thereof above the top of said chimney member.

6. In a lamp device, in combination, an annular support member; a tubular chimney member resting at its bottom on said annular support member, said chimney member being open at its top and being formed with a transverse bridge portion extending across its top, said bridge portion being formed with upwardly extending lateral flanges formed with slots extending axially of said chimney member, said chimney member being formed at one side with an air chamber opening externally thereof; fuel vaporizing means extending into said air chamber; an inverted U-shaped mixing tube opening at one end adjacent said fuel vaporizing means into said air chamber and having burner means at its other end, said mixing tube having adjustable connecting means at its bend portion extending into and movable along said slots in said flanges for mounting said mixing tube on said flanges in different positions axially of said chimney member; and a hood member extending over said chimney member and connected thereto adjacent the upper edge thereof in fluid tight engagement therewith, said hood member being formed with apertures in the portion thereof above the top of said chimney member.

7. In a lamp device, in combination, an annular support member; a tubular chimney member resting at its bottom on said annular support member, said chimney member being open at its top and having a transverse bridge portion, said bridge portion having flange means extending axially of said chimney member upwardly from the top thereof, said chimney member having an air chamber opening externally thereofgfuel vaporizing means extending into said air chamber; mixing tube means opening at one end into said air chamber and carrying burner means at its other end; adjusting means carrying said mixing tube means and being adjustably connected to said flange means of said bridge portion for axial movement to different positions so as to adjust the position of said mixing means; and a hood member extending over said chimney member along the entire length thereof and connected thereto adjacent the upper edge thereof in fluid tight engagement therewith, said hood member forming an annular chamber around said chimney member intermediate its ends communicating with said air chamber and being formed with apertures opening into said annular chamber and in the portion thereof above the top of said chimney member.

8. In a lamp device, in combination, an annular support member; a tubular chimney member resting at its bottom on said annular support member, said chimney member being open at its top and being formed with a transverse bridge portion extending across its top, said bridge portion being formed with upwardly extending lateral flanges formed with slots extending axially of said chimney member, said chimney member being formed at one side with an air chamber opening externally thereof; fuel vaporizing means extending into said air chamber; an inverted U-shaped mixing tube having one leg opening at one end adjacent said fuel vaporizing means into said air chamber and having burner means at the open end of its other leg, said other leg extending substantially along the axis of said chimney member, said mixing tube having adjustable connecting means at its bend portion extending into and movable along said slots in said flanges for mounting said mixing tube on said flanges in different positions axially of said chimney member; adjustable spacing means extending between and engaging said legs of said mixing tube and operable for varying the spacing between said legs; and a hood member extending over said chimney member and connected thereto adjacent the upper edge thereof in fluid tight engagement therewith, said hood member being formed with apertures in the portion thereof above the top of said chimney member.

9. A chimney assembly for a lamp device, comprising in combination, a tubular chimney member open at its top and having a transverse bridge portion, said bridge portion having flange means extending axially of said chimney member, said chimney member having an air chamber opening externally thereof; mixing tube means opening at one end into said air chamber and adapted to have a burner means connected at its other end, said mixing tube means being mounted on said flange means of said bridge portion for adjustable axial movement; and a hood member extending over said chimney member and resting by gravity adjacent the upper edge thereof in fluid tight engagement therewith.

10. A chimney assembly for a lamp device, comprising in combination a tubular chimney member open at its top and having a transverse bridge portion extending across its top, said bridge portion having flange means extending upwardly axially of said chimney member, said chimney member having an air chamber opening externally thereof; mixing tube means opening at one end into said air chamber and adapted'to have a burner means connected at its other end, said mixing tube means being mounted on said flange means of said bridge portion for adjustable axial movement; and a hood member extending over said chimney member and resting by gravity adjacent the upper edge thereof in fluid tight engagement therewith.

11. A chimney assembly for a lamp device, comprising in combination, a tubular chimney member open at its top and having a transverse bridge portion extending across its top, said bridge portion having flange means extending upwardly axially of said chimney member, said chimney member having an air chamber opening externally thereof; inverted U-shaped mixing tube means opening at one end into said air chamber and adapted to have a burner means connected at its other end, said mixing tube means being mounted at its bend portion on said flange means of said bridge portion for adjustable axial movement; and a hood member extending over said chimney member and resting by gravity adjacent the upper edge thereof in fluid tight engagement therewith.

12. In a lamp device, in combination, an annular support member; a tubular chimney member resting at its bottom on said annular support member, said chimney member being open at its top and being formed with a transverse bridge portion extending across its top, said bridge portion being formed with upwardly extending lateral flanges formed with slots extending axially of said chimney member, said chimney member being formed at one side with an air chamber opening externally thereof; fuel vaporizing means extending into said air chamber; an inverted U-shaped mixing tube opening at one end adjacent said fuel vaporizing means into said air chamber and having burner means at its other end, said mixing tube having adjustable connecting means at its bend portion extending into and movable along said slots in said flanges for mounting said mixing tube on said flanges in diiferent positions axially of said chimney member; and a hood member extending over said chimney member along the entire length thereof and connected thereto adjacent ihe :upper edge; lthereof. in fluid-.tflght engagement therewith, said hood member. forming an "annular cham' her aroundcsaid chimney. member-intermediate its ends communicating with saidv airchamber and being formed' with apertures ropeninginto said annular chamber and 5 in the portion thereof above the" top of said chimney member.

Palmer Oct. 10, 1911' Misun Apr. 16; 1-918 Tullis Nov. 25, 1941 FOREIGN PATENTS GreatrBritain of 1910} Great Britain Jan. 17, 1939 

